Anti-shake apparatus

ABSTRACT

An anti-shake apparatus for image stabilizing comprises a movable unit and a controller. The movable unit is movable for an anti-shake operation. The controller stops the anti-shake operation after an exposure time and moves the movable unit to a first position after the anti-shake operation. The first position is a position of the movable unit before the exposure time and before the anti-shake operation. The controller moves the movable unit at a decelerated, low rate of speed before finishing its movement to the first position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of pending U.S. patent application Ser.No. 11/775,886, filed on Jul. 11, 2007, which claims priority toJapanese Application No. 2006-192712, filed Jul. 13, 2006 and JapaneseApplication No. 2006-192863, filed Jul. 13, 2006 the disclosures ofwhich are expressly incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an anti-shake apparatus for aphotographing apparatus, and in particular to the movement of themovable unit to a position so that the shock caused by the impactbetween the movable unit and the point of contact which stops itsmovement is mitigated.

2. Description of the Related Art

An anti-shake apparatus for a photographing apparatus is proposed. Theanti-shake apparatus corrects for the hand-shake effect by moving ahand-shake correcting lens or an imaging device on a plane that isperpendicular to the optical axis, corresponding to the amount ofhand-shake which occurs during imaging.

Japanese unexamined patent publication (KOKAI) No. 2005-292799 disclosesan anti-shake apparatus that has a guide supporting the movable unitthat moves for the anti-shake operation.

However, this anti-shake apparatus does not have a fixed-positioningmechanism that maintains the movable unit in a stationary position whenthe movable unit is not being driven (drive OFF state). Therefore, whenthe anti-shake operation is complete and the movable unit ceases to bedriven with its drive status set to the OFF state, the movable unit isallowed to move freely according to the force of gravity, stopping onlywhen it comes into contact with the part at the end of its range ofmovement. In the case where the movable unit makes contact with thispart at a high rate of speed, the impact between the movable unit andthe part may be large enough to break the contacting part or cause theoperator of the photographing apparatus including this anti-shakeapparatus to experience discomfort due to the shock of the contactingpart.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide ananti-shake apparatus (an image stabilizing apparatus) that restrains theshock when the movable unit, without a fixed-positioning mechanism,makes contact with the end of its range of movement after the controldriving the movable unit for the anti-shake operation is set to the OFFstate.

According to the present invention, an anti-shake apparatus (an imagestabilizing apparatus) comprises a movable unit and a controller. Themovable unit is movable for an anti-shake operation. The controllerstops the anti-shake operation after an exposure time and moves themovable unit to a first position after the anti-shake operation. Thefirst position is a position of the movable unit before the exposuretime and before the anti-shake operation. The controller moves themovable unit at a decelerated, low rate of speed before finishing itsmovement to the first position.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will be betterunderstood from the following description, with reference to theaccompanying drawings in which:

FIG. 1 is a perspective rear view of the first and second embodiments ofthe photographing apparatus viewed from the back side;

FIG. 2 is a front view of the photographing apparatus;

FIG. 3 is a circuit construction diagram of the photographing apparatus;

FIG. 4 is a flowchart that shows the main operation of the photographingapparatus in the first embodiment;

FIG. 5 is a flowchart that shows the detail of the interruption processof the timer in the first embodiment;

FIG. 6 is a figure that shows calculations in the anti-shake operation;

FIG. 7 is a graph that shows the relationship between a movementdistance of the movable unit and a period of time beginning with thecommencement of the movement of the movable unit in the firstembodiment;

FIG. 8 is a graph that shows the relationship between a period of timeand a movement speed of the movable unit in the first embodiment;

FIG. 9 is a flowchart that shows the main operation of the photographingapparatus in the second embodiment;

FIG. 10 is a flowchart that shows the detail of the interruption processof the timer in the second embodiment;

FIG. 11 is a graph that shows the relationship between a movementdistance of the movable unit and a period of time beginning with thecommencement of the movement of the movable unit in the secondembodiment;

FIG. 12 is a graph that shows the relationship between a period of timeand a movement speed of the movable unit in the second embodiment; and

FIG. 13 is a flowchart that shows the detail of the calculation forspecifying the second position in step S161 of FIG. 10 in the secondembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described below with reference to the first andsecond embodiments shown in the drawings. In the first and secondembodiments, the photographing apparatus 1 is a digital camera. A cameralens 67 of the photographing apparatus 1 has an optical axis LX.

In order to explain the direction in the first and second embodiments, afirst direction x, a second direction y, and a third direction z aredefined (see FIG. 1). The first direction x is a direction which isperpendicular to the optical axis LX. The second direction y is adirection which is perpendicular to the optical axis LX and the firstdirection x. The third direction z is a direction which is parallel tothe optical axis LX and perpendicular to both the first direction x andthe second direction y.

The first embodiment is explained as follows.

The imaging part of the photographing apparatus 1 comprises a PON button11, a PON switch 11 a, a photometric switch 12 a, a release button 13, arelease switch 13 a, an anti-shake button 14, an anti-shake switch 14 a,an indicating unit 17 such as an LCD monitor etc., amirror-aperture-shutter unit 18, a DSP 19, a CPU 21, an AE (automaticexposure) unit 23, an AF (automatic focus) unit 24, an imaging unit 39 ain the anti-shake unit 30, and a camera lens 67 (see FIGS. 1, 2, and 3).

Whether the PON switch 11 a is in the ON state or the OFF state, isdetermined by the state of the PON button 11, so that the ON/OFF statesof the photographing apparatus 1 correspond to the ON/OFF states of thePON switch 11 a.

The photographic subject image is captured as an optical image throughthe camera lens 67 by the imaging unit 39 a, and the captured image isdisplayed on the indicating unit 17. The photographic subject image canbe optically observed by the optical finder (not depicted).

When the release button 13 is partially depressed by the operator, thephotometric switch 12 a changes to the ON state so that the photometricoperation, the AF sensing operation, and the focusing operation areperformed.

When the release button 13 is fully depressed by the operator, therelease switch 13 a changes to the ON state so that the imagingoperation by the imaging unit 39 a (the imaging apparatus) is performed,and the image, which is captured, is stored.

In the first embodiment, the anti-shake operation is performed only whenthe release switch 13 a is set to the ON state during the time ofexposure. The movable unit 30 a is moved to the first position P1 overthe course of (while taking the duration of) a predetermined length oftime after the exposure time of the imaging operation.

The mirror-aperture-shutter unit 18 is connected to port P7 of the CPU21 and performs an UP/DOWN operation of the mirror (a mirror-upoperation and a mirror-down operation), an OPEN/CLOSE operation of theaperture, and an OPEN/CLOSE operation of the shutter corresponding tothe ON state of the release switch 13 a.

The DSP 19 is connected to port P9 of the CPU 21, and it is connected tothe imaging unit 39 a. Based on a command from the CPU 21, the DSP 19performs the calculation operations, such as the image processingoperation etc., on the image signal obtained by the imaging operation ofthe imaging unit 39 a.

The CPU 21 is a control apparatus that controls each part of thephotographing apparatus 1 regarding the imaging operation and theanti-shake operation (i.e. the image stabilizing operation). Theanti-shake operation includes both the movement of the movable unit 30 aand position-detection efforts.

Further, the CPU 21 stores a value of the anti-shake parameter IS thatdetermines whether the photographing apparatus 1 is in the anti-shakemode or not, a value of a release state parameter RP, a value of amirror state parameter MP, a value of a mirror-down time parameter MRDN,a value of a first previous exposure position parameter RLSPx, a valueof a second previous exposure position parameter RLSPy, a value of afirst present position parameter PPx, and a second present positionparameter PPy.

The value of the release state parameter RP changes with respect to therelease sequence operation. When the release sequence operation isperformed, the value of the release state parameter RP is set to 1 (seesteps S22 to S32 in FIG. 4), and when the release sequence operation isfinished, the value of the release state parameter RP is set (reset) to0 (see steps S13 and S32 in FIG. 4).

When the mirror-down operation is being performed after the exposuretime for the imaging operation, the value of the mirror state parameterMP is set to 1 (see step S26 in FIG. 4); otherwise, the value of themirror state parameter MP is set to 0 (see step S28 in FIG. 4).

Whether the mirror-up operation of the photographing apparatus 1 isfinished is determined by the detection of the ON/OFF state of themechanical switch (not depicted). Whether the mirror-down operation ofthe photographing apparatus 1 is finished is determined by the detectionof the completion of the shutter charge.

The mirror-down time parameter MRDN is a parameter that measures thelength of time while the mirror-down operation is performed (see stepS60 in FIG. 5).

The CPU 21 stops driving the movable unit 30 a for the anti-shakeoperation after the exposure time of the imaging operation (set to theOFF state). If the movement of the movable unit 30 a for the anti-shakeoperation is stopped (set to the OFF state) and another drivingoperation of the movable unit 30 a is not performed, the movable unit 30a drops to the end of the range of movement according to the force ofgravity (drop movement).

In the first embodiment, after the movement of the movable unit 30 a forthe anti-shake operation is set to the OFF state, the CPU 21 drives themovable unit 30 a for a predetermined length of time (90 ms).

Specifically, after the value of the mirror state parameter MP is set to1, the CPU 21 moves the movable unit 30 a to a first position P1 whiletaking the duration of a predetermined length of time (90 ms) to do so.The first position P1 is the position of the movable unit 30 a in animmediately before the OFF state of driving, in other words, a positionof the movable unit 30 a after the release switch 13 a is set to the ONstate, before the exposure time, and before the anti-shake operation isperformed.

At a point in time before the exposure time but after the release switch13 a is set to the ON state, the anti-shake operation has not beenperformed yet, the control driving the movable unit 30 a for theanti-shake operation is set to the OFF state, and the movable unit 30 ais located at the end of the range of movement according to the effectsof gravity. Therefore, the first position P1 is somewhere at the end ofthe range of movement.

However, in the case where the magnitude of the movement of the movableunit 30 a under the force of gravity is small, such as when thephotographing apparatus 1 faces towards the up side or down side etc.,the first position P1 may be somewhere in the range of movement otherthan at an endpoint.

In the movement of the movable unit 30 a to the first position P1, themovable unit 30 a moves at a low speed immediately before finishing itsmovement (when the movable unit 30 a is near the first position P1).

Or, before finishing its movement, the movable unit 30 a decelerates(slows down) then stops upon completion of the movement.

Specifically, the CPU 21 controls the movement of the movable unit 30 a,under the condition where the relationship between a movement distanceof the movable unit 30 a and a period of time beginning with thecommencement of the movement of the movable unit 30 a is represented bya sine waveform (see FIG. 7), from the commencement of the movement ofthe movable unit 30 a (MRDN=0, the elapsed time t=0) to the completionof the movement of the movable unit 30 a (MRDN=90, the elapsed time t=90ms).

In other words, the CPU 21 controls the movement of the movable unit 30a, under the condition where the relationship between the speed ofmovement of the movable unit 30 a and the corresponding period of timeis represented by a cosine waveform (see FIG. 8) from the commencementof the movement of the movable unit 30 a (MRDN=0, the elapsed time t=0)to the completion of the movement of the movable unit 30 a (MRDN=90, theelapsed time t=90 ms).

The first previous exposure position parameter RLSPx is set equal to theposition of the movable unit 30 a (the first position P1) in the firstdirection x at the point in time when the release switch 13 a is set tothe ON state and before the exposure time (see step S21 in FIG. 4).

Similarly, the second previous exposure position parameter RLSPy is setequal to the position of the movable unit 30 a (the first position P1)in the second direction y at the point in time when the release switch13 a is set to the ON state and before the exposure time.

The first present position parameter PPx is set equal to the position ofthe movable unit 30 a in the first direction x at the point in timecorresponding to the commencement of the movement of the movable unit 30a to the first position P1 over the course of the predetermined lengthof time (90 ms) (see step S57 in FIG. 5).

Similarly, the second present position parameter PPy is set equal to theposition of the movable unit 30 a in the second direction y at the pointin time corresponding to the commencement of the movement of the movableunit 30 a to the first position P1 over the course of the predeterminedlength of time (90 ms).

Further, the CPU 21 stores values of a first digital angular velocitysignal Vx_(n), a second digital angular velocity signal Vy_(n), a firstdigital angular velocity VVx_(n), a second digital angular velocityVVy_(n), a digital displacement angle Bx_(n), a second digitaldisplacement angle By_(n), a coordinate of position S_(n) in the firstdirection x: Sx_(n), a coordinate of position S_(n) in the seconddirection y: Sy_(n), a first driving force Dx_(n), a second drivingforce Dy_(n), a coordinate of position P_(n) after A/D conversion in thefirst direction x: pdx_(n), a coordinate of position P_(n) after A/Dconversion in the second direction y: pdy_(n), a first subtraction valueex_(n), a second subtraction value ey_(n), a first proportionalcoefficient Kx, a second proportional coefficient Ky, a sampling cycle θof the anti-shake operation, a first integral coefficient Tix, a secondintegral coefficient Tiy, a first differential coefficient Tdx, and asecond differential coefficient Tdy.

The AE unit (an exposure calculating unit) 23 performs the photometricoperation and calculates the photometric values, based on the subjectbeing photographed. The AE unit 23 also calculates the aperture valueand the time length of the exposure, with respect to the photometricvalues, both of which are needed for imaging. The AF unit 24 performsthe AF sensing operation and the corresponding focusing operation, bothof which are needed for imaging. In the focusing operation, the cameralens 67 is re-positioned along the optical axis in the LX direction.

The anti-shake part (the anti-shake apparatus) of the photographingapparatus 1 comprises an anti-shake button 14, an anti-shake switch 14a, an indicating unit 17, a CPU 21, an angular velocity detection unit25, a driver circuit 29, an anti-shake unit 30, a hall-elementsignal-processing unit 45 (a magnetic-field change-detecting element),and the camera lens 67.

When the anti-shake button 14 is depressed by the operator, theanti-shake switch 14 a is changed to the ON state so that the anti-shakeoperation, in which the angular velocity detection unit 25 and theanti-shake unit 30 are driven independently of the other operationswhich include the photometric operation etc., is carried out at thepredetermined time interval. When the anti-shake switch 14 a is in theON state, in other words in the anti-shake mode, the anti-shakeparameter IS is set to 1 (IS=1). When the anti-shake switch 14 a is notin the ON state, in other words in the non-anti-shake mode, theanti-shake parameter IS is set to 0 (IS=0). In the first embodiment, thevalue of the predetermined time interval is set to 1 ms.

The various output commands corresponding to the input signals of theseswitches are controlled by the CPU 21.

The information regarding whether the photometric switch 12 a is in theON state or OFF state is input to port P12 of the CPU 21 as a 1-bitdigital signal. The information regarding whether the release switch 13a is in the ON state or OFF state is input to port P13 of the CPU 21 asa 1-bit digital signal. The information regarding whether the anti-shakeswitch 14 a is in the ON state or OFF state is input to port P14 of theCPU 21 as a 1-bit digital signal.

The AE unit 23 is connected to port P4 of the CPU 21 for inputting andoutputting signals. The AF unit 24 is connected to port P5 of the CPU 21for inputting and outputting signals. The indicating unit 17 isconnected to port P6 of the CPU 21 for inputting and outputting signals.

Next, the details of the input and output relationships between the CPU21 and the angular velocity detection unit 25, the driver circuit 29,the anti-shake unit 30, and the hall-element signal-processing unit 45are explained.

The angular velocity detection unit 25 has a first angular velocitysensor 26 a, a second angular velocity sensor 26 b, a first high-passfilter circuit 27 a, a second high-pass filter circuit 27 b, a firstamplifier 28 a and a second amplifier 28 b.

The first angular velocity sensor 26 a detects the angular velocity of arotary motion (the yawing) of the photographing apparatus 1 about theaxis of the second direction y (the velocity-component in the firstdirection x of the angular velocity of the photographing apparatus 1).The first angular velocity sensor 26 a is a gyro sensor that detects ayawing angular velocity.

The second angular velocity sensor 26 b detects the angular velocity ofa rotary motion (the pitching) of the photographing apparatus 1 aboutthe axis of the first direction x (detects the velocity-component in thesecond direction y of the angular velocity of the photographingapparatus 1). The second angular velocity sensor 26 b is a gyro sensorthat detects a pitching angular velocity.

The first high-pass filter circuit 27 a reduces a low frequencycomponent of the signal output from the first angular velocity sensor 26a, because the low frequency component of the signal output from thefirst angular velocity sensor 26 a includes signal elements that arebased on a null voltage and a panning-motion, neither of which arerelated to hand-shake.

The second high-pass filter circuit 27 b reduces a low frequencycomponent of the signal output from the second angular velocity sensor26 b, because the low frequency component of the signal output from thesecond angular velocity sensor 26 b includes signal elements that arebased on a null voltage and a panning-motion, neither of which arerelated to hand-shake.

The first amplifier 28 a amplifies a signal regarding the yawing angularvelocity, whose low frequency component has been reduced, and outputsthe analog signal to the A/D converter A/D 0 of the CPU 21 as a firstangular velocity vx.

The second amplifier 28 b amplifies a signal regarding the pitchingangular velocity, whose low frequency component has been reduced, andoutputs the analog signal to the A/D converter A/D 1 of the CPU 21 as asecond angular velocity vy.

The reduction of the low frequency signal component is a two-stepprocess; the primary part of the analog high-pass filter processingoperation is performed first by the first and second high-pass filtercircuits 27 a and 27 b, followed by the secondary part of the digitalhigh-pass filter processing operation that is performed by the CPU 21.

The cut off frequency of the secondary part of the digital high-passfilter processing operation is higher than that of the primary part ofthe analog high-pass filter processing operation.

In the digital high-pass filter processing operation, the value of atime constant (a first high-pass filter time constant hx and a secondhigh-pass filter time constant hy) can be easily changed.

The supply of electric power to the CPU 21 and each part of the angularvelocity detection unit 25 begins after the PON switch 11 a is set tothe ON state (the main power supply is set to the ON state). Thecalculation of a hand-shake quantity begins after the PON switch 11 a isset to the ON state.

The CPU 21 converts the first angular velocity vx, which is input to theA/D converter A/D 0, to a first digital angular velocity signal Vx_(n)(A/D conversion operation); calculates a first digital angular velocityVVx_(n) by reducing a low frequency component of the first digitalangular velocity signal Vx_(n) (the digital high-pass filter processingoperation) because the low frequency component of the first digitalangular velocity signal Vx_(n) includes signal elements that are basedon a null voltage and a panning-motion, neither of which are related tohand-shake; and calculates a hand shake quantity (a hand shakedisplacement angle: a first digital displacement angle Bx_(n)) byintegrating the first digital angular velocity VVx_(n) (the integrationprocessing operation).

Similarly the CPU 21 converts the second angular velocity vy, which isinput to the A/D converter A/D 1, to a second digital angular velocitysignal Vy_(n) (A/D conversion operation); calculates a second digitalangular velocity VVy_(n) by reducing a low frequency component of thesecond digital angular velocity signal Vy_(n) (the digital high-passfilter processing operation) because the low frequency component of thesecond digital angular velocity signal Vy_(n) includes signal elementsthat are based on a null voltage and a panning-motion, neither of whichare related to hand-shake; and calculates a hand shake quantity (a handshake displacement angle: a second digital displacement angle By_(n)) byintegrating the second digital angular velocity VVy_(n) (the integrationprocessing operation).

Accordingly, the CPU 21 and the angular velocity detection unit 25 use afunction to calculate the hand-shake quantity.

“n” is an integer that is greater than 0, and indicates a length of time(ms) from the point when the interruption process of the timercommences, (t=0, and see step S12 in FIG. 4) to the point when thelatest anti-shake operation is performed (t=n).

In the digital high-pass filter processing operation regarding the firstdirection x, the first digital angular velocity VVx_(n) is calculated bydividing the summation of the first digital angular velocity VVx₀ toVVx_(n-1) calculated by the interruption process of the timer before the1 ms predetermined time interval (before the latest anti-shake operationis performed), by the first high-pass filter time constant hx, and thensubtracting the resulting quotient from the first digital angularvelocity signal Vx_(n) (VVx_(n)=Vx_(n)−(ΣVVx_(n-1))÷hx, see (1) in FIG.6).

In the digital high-pass filter processing operation regarding thesecond direction y, the second digital angular velocity VVy_(n) iscalculated by dividing the summation of the second digital angularvelocity VVy₀ to VVy_(n-1) calculated by the interruption process of thetimer before the 1 ms predetermined time interval (before the latestanti-shake operation is performed), by the second high-pass filter timeconstant hy, and then subtracting the resulting quotient from the seconddigital angular velocity signal Vy_(n) (VVy_(n)=Vy_(n)−(ΣVVy_(n-1))÷hy).

In the first embodiment, the angular velocity detection operation in(portion of) the interruption process of the timer includes a process inthe angular velocity detection unit 25 and a process of inputtingprocess of the first and second angular velocities vx and vy from theangular velocity detection unit 25 to the CPU 21.

In the integration processing operation regarding the first direction x,the first digital displacement angle Bx_(n) is calculated by thesummation from the first digital angular velocity VVx₀ at the point whenthe interruption process of the timer commences, t=0, (see step S12 inFIG. 4) to the first digital angular velocity VVx_(n) at the point whenthe latest anti-shake operation is performed (t=n), (Bx_(n)=ΣVVx_(n),see (3) in FIG. 6).

Similarly, in the integration processing operation regarding the seconddirection y, the second digital displacement angle By_(n) is calculatedby the summation from the second digital angular velocity VVy₀ at thepoint when the interruption process of the timer commences to the seconddigital angular velocity VVy_(n) at the point when the latest anti-shakeoperation is performed (By_(n)=ΣVVy_(n)).

The CPU 21 calculates the position S_(n) where the imaging unit 39 a(the movable unit 30 a) should be moved, corresponding to the hand-shakequantity (the first and second digital displacement angles Bx_(n) andBy_(n)) calculated for the first direction x and the second direction y,based on a position conversion coefficient zz (a first positionconversion coefficient zx for the first direction x and a secondposition conversion coefficient zy for the second direction y).

The coordinate of position S_(n) in the first direction x is defined asSx_(n), and the coordinate of position S_(n) in the second direction yis defined as Sy_(n). The movement of the movable unit 30 a, whichincludes the imaging unit 39 a, is performed by using electro-magneticforce and is described later.

The driving force D_(n) drives the driver circuit 29 in order to movethe movable unit 30 a to the position S_(n). The coordinate of thedriving force D_(n) in the first direction x is defined as the firstdriving force Dx_(n) (after D/A conversion: a first PWM duty dx). Thecoordinate of the driving force D_(n) in the second direction y isdefined as the second driving force Dy_(n) (after D/A conversion: asecond PWM duty dy).

In the first embodiment, the position S_(n) where the imaging unit 39 a(the movable unit 30 a) should be moved during the predetermined periodhaving the predetermined length of time after the completion anti-shakeoperation, is not set to the value that corresponds to the hand-shakequantity, but is instead set to the value for moving the movable unit 30a to the first position P1 over the course of the predetermined periodof time (see step S59 in FIG. 5).

In a positioning operation regarding the first direction x, thecoordinate of position S_(n) in the first direction x is defined asSx_(n), and is the product of the latest first digital displacementangle Bx_(n) and the first position conversion coefficient zx(Sx_(n)=zx×Bx_(n), see (3) in FIG. 6).

In a positioning operation regarding the second direction y, thecoordinate of position S_(n) in the second direction y is defined asSy_(n), and is the product of the latest second digital displacementangle By_(n) and the second position conversion coefficient zy(Sy_(n)=zy×By_(n)).

The anti-shake unit 30 is an apparatus that corrects for the hand-shakeeffect by moving the imaging unit 39 a to the position S_(n), bycanceling the lag of the photographing subject image on the imagingsurface of the imaging device of the imaging unit 39 a, and bystabilizing the photographing subject image displayed on the imagingsurface of the imaging device, during the exposure time and when theanti-shake operation is performed (IS=1).

The anti-shake unit 30 has a fixed unit 30 b, and a movable unit 30 awhich includes the imaging unit 39 a and can be moved about on the xyplane.

During the exposure time when the anti-shake operation is not performed(IS=0), the movable unit 30 a is fixed to (held at) a predeterminedposition. In the first embodiment, the predetermined position is at thecenter of the range of movement.

During the predetermined period following the time of exposure, themovable unit 30 a is driven (moved) to the first position P1; otherwise(except for during the time of exposure and the predetermined periodfollowing the time of exposure), the movable unit 30 a is not driven(moved).

The anti-shake unit 30 does not have a fixed-positioning mechanism thatmaintains the movable unit 30 a in a fixed (held) position when themovable unit 30 a is not being driven (drive OFF state).

The driving of the movable unit 30 a of the anti-shake unit 30,including movement to a predetermined fixed (held) position, isperformed by the electro-magnetic force of the coil unit for driving andthe magnetic unit for driving, through the driver circuit 29 which hasthe first PWM duty dx input from the PWM 0 of the CPU 21 and has thesecond PWM duty dy input from the PWM 1 of the CPU 21 (see (5) in FIG.6).

The detected-position P_(n) of the movable unit 30 a, either before orafter the movement effected by the driver circuit 29, is detected by thehall element unit 44 a and the hall-element signal-processing unit 45.

Information regarding the first coordinate of the detected-positionP_(n) in the first direction x, in other words a first detected-positionsignal px, is input to the A/D converter A/D 2 of the CPU 21 (see (2) inFIG. 6). The first detected-position signal px is an analog signal thatis converted to a digital signal by the A/D converter A/D 2 (A/Dconversion operation). The first coordinate of the detected-positionP_(n) in the first direction x, after the A/D conversion operation, isdefined as pdx_(n) and corresponds to the first detected-position signalpx.

Information regarding the second coordinate of the detected-positionP_(n) in the second direction y, in other words a seconddetected-position signal py, is input to the A/D converter A/D 3 of theCPU 21. The second detected-position signal py is an analog signal thatis converted to a digital signal by the A/D converter A/D 3 (A/Dconversion operation). The second coordinate of the detected-positionP_(n) in the second direction y, after the A/D conversion operation, isdefined as pdy_(n) and corresponds to the second detected-positionsignal py.

The PID (Proportional Integral Differential) control calculates thefirst and second driving forces Dx_(n) and Dy_(n) on the basis of thecoordinate data for the detected-position P_(n) (pdx_(n), pdy_(n)) andthe position S_(n) (Sx_(n), Sy_(n)) following movement.

The calculation of the first driving force Dx_(n) is based on the firstsubtraction value ex_(n), the first proportional coefficient Kx, thesampling cycle θ, the first integral coefficient Tix, and the firstdifferential coefficient Tdx(Dx_(n)=Kx×{ex_(n)+θ÷Tix×Σex_(n)+Tdx÷θ×(ex_(n)−ex_(n-1))}, see (4) inFIG. 6). The first subtraction value ex_(n) is calculated by subtractingthe first coordinate of the detected-position P_(n) in the firstdirection x after the A/D conversion operation, pdx_(n), from thecoordinate of position S_(n) in the first direction x, Sx_(n)(ex_(n)=Sx_(n)−pdx_(n)).

The calculation of the second driving force Dy_(n) is based on thesecond subtraction value ey_(n), the second proportional coefficient Ky,the sampling cycle θ, the second integral coefficient Tiy, and thesecond differential coefficient Tdy(Dy_(n)=Ky×{ey_(n)+θ÷Tiy×Σey_(n)+Tdy÷θ×(ey_(n)−ey_(n-1))}). The secondsubtraction value ey_(n) is calculated by subtracting the secondcoordinate of the detected-position P_(n) in the second direction yafter the A/D conversion operation, pdy_(n), from the coordinate ofposition S_(n) in the second direction y, Sy_(n)(ey_(n)=Sy_(n)−Pdy_(n)).

The value of the sampling cycle θ is set to a predetermined timeinterval of 1 ms.

Driving the movable unit 30 a to the position S_(n), (Sx_(n), Sy_(n))corresponding to the anti-shake operation of the PID control, isperformed when the photographing apparatus 1 is in the anti-shake mode(IS=1) where the anti-shake switch 14 a is set to the ON state.

When the anti-shake parameter IS is 0, the PID control that does notcorrespond to the anti-shake operation is performed so that the movableunit 30 a is moved to the center of the range of movement (thepredetermined position).

The movable unit 30 a has a coil unit for driving that is comprised of afirst driving coil 31 a and a second driving coil 32 a, an imaging unit39 a that has the imaging device, and a hall element unit 44 a as amagnetic-field change-detecting element unit. In the first embodiment,the imaging device is a CCD; however, the imaging device may be anotherimaging device such as a CMOS etc.

The fixed unit 30 b has a magnetic unit for driving that is comprised ofa first position-detecting and driving magnet 411 b, a secondposition-detecting and driving magnet 412 b, a first position-detectingand driving yoke 431 b, and a second position-detecting and driving yoke432 b.

The fixed unit 30 b movably supports the movable unit 30 a in the firstdirection x and in the second direction y.

When the center area of the imaging device is intersected by the opticalaxis LX of the camera lens 67, the relationship between the position ofthe movable unit 30 a and the position of the fixed unit 30 b isarranged so that the movable unit 30 a is positioned at the center ofits range of movement in both the first direction x and the seconddirection y, in order to utilize the full size of the imaging range ofthe imaging device.

A rectangle shape, which is the form of the imaging surface of theimaging device, has two diagonal lines. In the first embodiment, thecenter of the imaging device is at the intersection of these twodiagonal lines.

The first driving coil 31 a, the second driving coil 32 a, and the hallelement unit 44 a are attached to the movable unit 30 a.

The first driving coil 31 a forms a seat and a spiral shaped coilpattern. The coil pattern of the first driving coil 31 a has lines whichare parallel to the second direction y, thus creating the firstelectro-magnetic force to move the movable unit 30 a that includes thefirst driving coil 31 a, in the first direction x.

The first electro-magnetic force occurs on the basis of the currentdirection of the first driving coil 31 a and the magnetic-fielddirection of the first position-detecting and driving magnet 411 b.

The second driving coil 32 a forms a seat and a spiral shaped coilpattern. The coil pattern of the second driving coil 32 a has lineswhich are parallel to the first direction x, thus creating the secondelectro-magnetic force to move the movable unit 30 a that includes thesecond driving coil 32 a, in the second direction y.

The second electro-magnetic force occurs on the basis of the currentdirection of the second driving coil 32 a and the magnetic-fielddirection of the second position-detecting and driving magnet 412 b.

The first and second driving coils 31 a and 32 a are connected to thedriver circuit 29, which drives the first and second driving coils 31 aand 32 a, through the flexible circuit board (not depicted). The firstPWM duty dx is input to the driver circuit 29 from the PWM 0 of the CPU21, and the second PWM duty dy is input to the driver circuit 29 fromthe PWM 1 of the CPU 21. The driver circuit 29 supplies power to thefirst driving coil 31 a that corresponds to the value of the first PWMduty dx, and to the second driving coil 32 a that corresponds to thevalue of the second PWM duty dy, to drive the movable unit 30 a.

The first position-detecting and driving magnet 411 b is attached to themovable unit side of the fixed unit 30 b, where the firstposition-detecting and driving magnet 411 b faces the first driving coil31 a and the horizontal hall element hh10 in the third direction z.

The second position-detecting and driving magnet 412 b is attached tothe movable unit side of the fixed unit 30 b, where the secondposition-detecting and driving magnet 412 b faces the second drivingcoil 32 a and the vertical hall element hv10 in the third direction z.

The first position-detecting and driving magnet 411 b is attached to thefirst position-detecting and driving yoke 431 b, under the conditionwhere the N pole and S pole are arranged in the first direction x. Thefirst position-detecting and driving yoke 431 b is attached to the fixedunit 30 b, on the side of the movable unit 30 a, in the third directionz.

The second position-detecting and driving magnet 412 b is attached tothe second position-detecting and driving yoke 432 b, under thecondition where the N pole and S pole are arranged in the seconddirection y. The second position-detecting and driving yoke 432 b isattached to the fixed unit 30 b, on the side of the movable unit 30 a,in the third direction z.

The first and second position-detecting and driving yokes 431 b, 432 bare made of a soft magnetic material.

The first position-detecting and driving yoke 431 b prevents themagnetic-field of the first position-detecting and driving magnet 411 bfrom dissipating to the surroundings, and raises the magnetic-fluxdensity between the first position-detecting and driving magnet 411 band the first driving coil 31 a, and between the firstposition-detecting and driving magnet 411 b and the horizontal hallelement hh10.

The second position-detecting and driving yoke 432 b prevents themagnetic-field of the second position-detecting and driving magnet 412 bfrom dissipating to the surroundings, and raises the magnetic-fluxdensity between the second position-detecting and driving magnet 412 band the second driving coil 32 a, and between the secondposition-detecting and driving magnet 412 b and the vertical hallelement hv10.

The hall element unit 44 a is a single-axis unit that contains twomagnetoelectric converting elements (magnetic-field change-detectingelements) utilizing the Hall Effect to detect the firstdetected-position signal px and the second detected-position signal pyspecifying the first coordinate in the first direction x and the secondcoordinate in the second direction y, respectively, of the presentposition P_(n) of the movable unit 30 a.

One of the two hall elements is a horizontal hall element hh10 fordetecting the first coordinate of the position P_(n) of the movable unit30 a in the first direction x, and the other is a vertical hall elementhv10 for detecting the second coordinate of the position P_(n) of themovable unit 30 a in the second direction y.

The horizontal hall element hh10 is attached to the movable unit 30 a,where the horizontal hall element hh10 faces the firstposition-detecting and driving magnet 411 b of the fixed unit 30 b inthe third direction z.

The vertical hall element hv10 is attached to the movable unit 30 a,where the vertical hall element hv10 faces the second position-detectingand driving magnet 412 b of the fixed unit 30 b in the third directionz.

When the center of the imaging device intersects the optical axis LX, itis desirable to have the horizontal hall element hh10 positioned on thehall element unit 44 a facing an intermediate area between the N poleand S pole of the first position-detecting and driving magnet 411 b inthe first direction x, as viewed from the third direction z. In thisposition, the horizontal hall element hh10 utilizes the maximum range inwhich an accurate position-detecting operation can be performed based onthe linear output-change (linearity) of the single-axis hall element.

Similarly, when the center of the imaging device intersects the opticalaxis LX, it is desirable to have the vertical hall element hv10positioned on the hall element unit 44 a facing an intermediate areabetween the N pole and S pole of the second position-detecting anddriving magnet 412 b in the second direction y, as viewed from the thirddirection z.

The hall-element signal-processing unit 45 has a first hall-elementsignal-processing circuit 450 and a second hall-elementsignal-processing circuit 460.

The first hall-element signal-processing circuit 450 detects ahorizontal potential-difference x10 between the output terminals of thehorizontal hall element hh10 that is based on an output signal of thehorizontal hall element hh10.

The first hall-element signal-processing circuit 450 outputs the firstdetected-position signal px, which specifies the first coordinate of theposition P_(n) of the movable unit 30 a in the first direction x, to theA/D converter A/D 2 of the CPU 21, on the basis of the horizontalpotential-difference x10.

The second hall-element signal-processing circuit 460 detects a verticalpotential-difference y10 between the output terminals of the verticalhall element hv10 that is based on an output signal of the vertical hallelement hv10.

The second hall-element signal-processing circuit 460 outputs the seconddetected-position signal py, which specifies the second coordinate ofthe position P_(n) of the movable unit 30 a in the second direction y,to the A/D converter A/D 3 of the CPU 21, on the basis of the verticalpotential-difference y10.

Next, the main operation of the photographing apparatus 1 in the firstembodiment is explained by using the flowchart in FIG. 4.

When the photographing apparatus 1 is set to the ON state, theelectrical power is supplied to the angular velocity detection unit 25so that the angular velocity detection unit 25 is set to the ON state instep S11.

In step S12, the interruption process of the timer at the predeterminedtime interval (1 ms) commences. In step S13, the value of the releasestate parameter RP is set to 0. The detail of the interruption processof the timer in the first embodiment is explained later by using theflowchart in FIG. 5.

In step S14, it is determined whether the photometric switch 12 a is setto the ON state. When it is determined that the photometric switch 12 ais not set to the ON state, the operation returns to step S14 and theprocess in step S14 is repeated. Otherwise, the operation continues onto step S15.

In step S15, it is determined whether the anti-shake switch 14 a is setto the ON state. When it is determined that the anti-shake switch 14 ais not set to the ON state, the value of the anti-shake parameter IS isset to 0 in step S16. Otherwise, the value of the anti-shake parameterIS is set to 1 in step S17.

In step S18, the AE sensor of the AE unit 23 is driven, the photometricoperation is performed, and the aperture value and exposure time arecalculated.

In step S19, the AF sensor and the lens control circuit of the AF unit24 are driven to perform the AF sensing and focus operations,respectively.

In step S20, it is determined whether the release switch 13 a is set tothe ON state. When the release switch 13 a is not set to the ON state,the operation returns to step S14 and the process in steps S14 to S19 isrepeated. Otherwise, the operation continues on to step S21.

In step S21, the first position P1 is specified. Specifically, the valueof the first previous exposure position parameter RLSPx is set to thevalue of the coordinate of the position P_(n) after A/D conversion inthe first direction x: pdx_(n), the value of the second previousexposure position parameter RLSPy is set to the value of the coordinateof the position P_(n) after A/D conversion in the second direction y:pdy_(n), and then the release sequence operation commences.

In step S22, the value of the release state parameter RP is set to 1.

In step S23, the mirror-up operation and the aperture closing operationcorresponding to the aperture value that is either preset or calculated,are performed by the mirror-aperture-shutter unit 18.

After the mirror-up operation is finished, the opening operation of theshutter (the movement of the front curtain in the shutter) commences instep S24.

In step S25, the exposure operation, or in other words the electriccharge accumulation of the imaging device (CCD etc.), is performed.After the exposure time has elapsed, the value of the mirror stateparameter MP is set to 1 and the value of the mirror-down time parameterMRDN is set to 0 in step S26.

In step S27, the closing operation of the shutter (the movement of therear curtain in the shutter), the mirror-down operation, and the openingoperation of the aperture are performed by the mirror-aperture-shutterunit 18. In step S28, the value of the mirror state parameter MP is setto 0.

After the time of exposure, the anti-shake operation is complete, andthe movement of the movable unit 30 a for the anti-shake operation ispostponed until the release switch 13 a is once again set to the ONstate. In other words, the interruption process in FIG. 5 is performedwithout executing the actions of steps S61 to S63 from after theexposure time until the next time the release switch 13 a is set to theON state.

The elapsed time from commencement to completion of the mirror-downoperation is approximately 120 ms. In the first embodiment, the movementof the movable unit 30 a to the first position P1 is finished before (orat the same time of) the completion of the mirror-down operation.

Further, when the completion of the movement of the movable unit 30 a tothe first position P1 is synchronized with the completion of themirror-down operation, the timing of the shock from the braking themovement of the movable unit 30 a agrees with the timing of the shockbased on the completion of the mirror-down operation. Therefore,discomfort that the operator of the photographing apparatus 1 feels canbe restrained because the shock based on breaking the movement of themovable unit 30 a is cancelled out.

In step S29, the electric charge which has accumulated in the imagingdevice during the exposure time is read. In step S30, the CPU 21communicates with the DSP 19 so that the image processing operation isperformed based on the electric charge read from the imaging device. Theimage, on which the image processing operation is performed, is storedto the memory in the photographing apparatus 1. In step S31, the imagethat is stored in the memory is displayed on the indicating unit 17. Instep S32, the value of the release state parameter RP is set to 0 sothat the release sequence operation is finished, and the operation thenreturns to step S14, in other words the photographing apparatus 1 is setto a state where the next imaging operation can be performed.

Next, the interruption process of the timer in the first embodiment,which commences in step S12 in FIG. 4 and is performed at everypredetermined time interval (1 ms) independent of the other operations,is explained by using the flowchart in FIG. 5.

When the interruption process of the timer commences, the first angularvelocity vx, which is output from the angular velocity detection unit25, is input to the A/D converter A/D 0 of the CPU 21 and converted tothe first digital angular velocity signal Vx_(n), in step S51. Thesecond angular velocity vy, which is also output from the angularvelocity detection unit 25, is input to the A/D converter A/D 1 of theCPU 21 and converted to the second digital angular velocity signalVy_(n) (the angular velocity detection operation).

The low frequencies of the first and second digital angular velocitysignals Vx_(n) and Vy_(n) are reduced in the digital high-pass filterprocessing operation (the first and second digital angular velocitiesVVx_(n) and VVy_(n)).

In step S52, it is determined whether the value of the release stateparameter RP is set to 1. When it is determined that the value of therelease state parameter RP is not set to 1, driving the movable unit 30a is set to OFF state, or the anti-shake unit 30 is set to a state wherethe driving control of the movable unit 30 a is not performed in stepS53. Otherwise, the operation proceeds directly to step S54.

In step S54, the hall element unit 44 a detects the position of themovable unit 30 a, and the first and second detected-position signals pxand py are calculated by the hall-element signal-processing unit 45. Thefirst detected-position signal px is then input to the A/D converter A/D2 of the CPU 21 and converted to a digital signal pdx_(n), whereas thesecond detected-position signal py is input to the A/D converter A/D 3of the CPU 21 and also converted to a digital signal pdy_(n), both ofwhich thus determine the present position P_(n) (pdx_(n), pdy_(n)) ofthe movable unit 30 a.

In step S55, it is determined whether the value of the mirror stateparameter MP is set to 1. When it is determined that the value of themirror state parameter MP is not set to 1, the operation proceedsdirectly to step S70. Otherwise, the operation continues to step S56.

In step S56, it is determined whether the value of the mirror-down timeparameter MRDN is set to 0.

When it is determined that the value of the mirror-down time parameterMRDN is set to 0, the value of the first present position parameter PPxis set to the value of the coordinate of the position P_(in) in thefirst direction x after A/D conversion, pdx_(n), and the value of thesecond present position parameter PPy is set to the value of thecoordinate of the position P_(n) in the second direction y after A/Dconversion, pdy_(n), in step S57. Then the operation continues to stepS58. Otherwise, the operation proceeds directly to step S58.

In step S58, it is determined whether the value of the mirror-down timeparameter MRDN is set to 90.

When it is determined that the value of the mirror-down time parameterMRDN is set to 90, the operation proceeds directly to step S53;otherwise, the operation continues to step S59.

In step S59, the position S_(n) (Sx_(n), Sy_(n)) where the movable unit30 a (the imaging unit 39 a) should be moved is calculated on the basisof the first and second present position parameters PPx and PPy, thefirst and second previous exposure position parameter RLSPx and RLSPy,and the mirror-down time parameter MRDN(Sx_(n)=PPx+(RLSPx−PPx)×sin(MRDN×90 degrees÷90),Sy_(n)=PPy+(RLSPy−PPy)×sin(MRDN×90 degrees÷90)).

In step S60, the value of the mirror-down time parameter MRDN isincreased by the value of 1, then the operation proceeds directly tostep S64.

Because a large load is exerted upon the CPU 21 when it performs thetrigonometric function processing operation to calculate the value of“sin(MRDN×90 degrees÷90)”, it is desirable to store the values of the 91different patterns of “sin(MRDN×90 degrees÷90)” from when the MRDN=0 towhen MRDN=90 in order to increase the processing speed.

In step S70, it is determined whether the value of the mirror-down timeparameter MRDN is set to 90. When it is determined that the value of themirror-down time parameter MRDN is set to 90, the operation proceeds tostep S53. Otherwise, the operation returns to step S61.

In step S61, it is determined whether the value of the anti-shakeparameter IS is 0. When it is determined that the value of theanti-shake parameter IS is 0 (IS=0), in other words when thephotographing apparatus is not in anti-shake mode, the position S_(n)(Sx_(n), Sy_(n)) where the movable unit 30 a (the imaging unit 39 a)should be moved is set at the center of the range of movement of themovable unit 30 a, in step S62. When it is determined that the value ofthe anti-shake parameter IS is not 0 (IS=1), in other words when thephotographing apparatus is in anti-shake mode, the position S_(n)(Sx_(n), Sy_(n)) where the movable unit 30 a (the imaging unit 39 a)should be moved is calculated on the basis of the first and secondangular velocities vx and vy, in step S63.

In step S64, the first driving force Dx_(n) (the first PWM duty dx) andthe second driving force Dy_(n) (the second PWM duty dy) of the drivingforce D, which moves the movable unit 30 a to the position S_(n), arecalculated on the basis of the position S_(n) (Sx_(n), Sy_(n)) that wasdetermined in step S59, step S62 or step S63, and the present positionP_(n) (pdx_(n), pdy_(n)).

In step S65, the first driving coil unit 31 a is driven by applying thefirst PWM duty dx to the driver circuit 29, and the second driving coilunit 32 a is driven by applying the second PWM duty dy to the drivercircuit 29, so that the movable unit 30 a is moved to position S_(n)(Sx_(n), Sy_(n)).

The process of steps S64 and S65 is an automatic control calculationthat is used with the PID automatic control for performing general(normal) proportional, integral, and differential calculations.

In an anti-shake apparatus that does not have a fixed-positioningmechanism so that the movable unit 30 a remains stationary when themovable unit 30 a is not being driven, such as the first embodiment,when the movement of the movable unit 30 a is set to the OFF state afterthe anti-shake operation, the movable unit 30 a is allowed to movefreely according to the force of gravity until it is stopped upon makingcontact with the end of its range of movement. In the case where theimpact between the movable unit 30 a and the contacting part is large,the contacting part may be broken and the operator of the photographingapparatus 1 may experience discomfort due to the shock of the movableunit 30 a.

In the first embodiment, when the anti-shake operation is complete andthe control driving the movable unit 30 a is set to the OFF state, themovable unit 30 a is moved to the first position P1 over the course ofthe predetermined length of time (90 ms). The first position P1 isdetermined based on the position in which the photographing apparatus 1is held by the operator before the exposure time, so that the positionof the photographing apparatus 1 held by the operator at the end of thetime of exposure time (the completion of the anti-shake operation) isapproximately the same as the position of the photographing apparatus 1held by the operator before the time of exposure.

Therefore, the position where the movable unit is moved according to theforce of gravity, upon completion of the anti-shake operation when thecontrol driving the movable unit 30 a is set to the OFF state, which issomewhere at the end of the range of movement, is almost the same as thefirst position P1.

Further, the movement of the movable unit 30 a to the first position P1is performed over the course of the predetermined length of time (90 ms)at a comparatively low speed (see FIG. 8). Particularly towards the endof finishing the movement (when the movable unit 30 a is near the firstposition P1), the movement of the movable unit 30 a is performed at thelow speed so that the shock based on the movement can be restrained.

Further, in the first embodiment, in order to move the movable unit 30 ato the first position P1, it is not necessary to specify the directionof the movement. Therefore, the calculation can be simplified comparedto the case where the direction of the movement of the movable unit 30 ais specified by detecting the direction of gravity etc.

In the first embodiment, the CPU 21 controls the movement of the movableunit 30 a, under the condition where the relationship between themovement distance of the movable unit 30 a and a period of timebeginning with the commencement of the movement of the movable unit 30 ais represented by the sine waveform (see FIG. 7) from the commencementof the movement of the movable unit 30 a (MRDN=0, the elapsed time t=0)to when the completion of the movement of the movable unit 30 a(MRDN=90, the elapsed time t=90 ms), after the anti-shake operation.

In other words, the CPU 21 controls the movement of the movable unit 30a, under the condition where the relationship between the speed of themovement of the movable unit 30 a and the corresponding period of timeis represented by the cosine waveform (see FIG. 8) from the commencementof the movement of the movable unit 30 a (MRDN=0, the elapsed time t=0)to the completion of the movement of the movable unit 30 a (MRDN=90, theelapsed time t=90 ms), after the anti-shake operation.

The movement of the movable unit 30 a to the first position P1 isperformed based on the position detection operation of the movable unit30 a and the positioning operation in which the position to where themovable unit 30 a should be moved is determined, at the predeterminedtime interval of 1 ms which is shorter than the predetermined period.

Therefore, the movement of the movable unit 30 a can be deceleratedsmoothly and stably, so that the speed of the movable unit 30 a isalmost 0 when the movable unit 30 a reaches the first position P1.

However, the waveform representing the relationship between the elapsedtime and the movement distance of the movable unit 30 a from the pointwhen the movement of the movable unit 30 a commences is not limited tothe sine waveform.

For example, the waveform that represents the relationship between themovement distance of the movable unit 30 a and the corresponding elapsedtime from the point when the movement of the movable unit 30 acommences, may be a saturation curve that the movement of the movableunit 30 a follows at the low speed immediately before the completion ofthe movement of the movable unit 30 a (MRDN=90).

Further, in the first embodiment, the photographing apparatus 1 is asingle lens reflex camera that performs the mirror-up/down operation;however, the photographing apparatus 1 may not perform themirror-up/down operation.

In the case where the photographing apparatus 1 that does not performthe mirror-up operation is used for the first embodiment, the movementof the movable unit 30 a to the first position P1 commences after theanti-shake operation is finished, and the movement of the movable unit30 a to the first position P1 is complete before the secondaryprocessing, such as the image processing operation etc., is complete.

Further, the length of the predetermined period is not limited 90 ms.The predetermined length of time is set to a time length that is shorterthan the length of time from the point when the anti-shake operation isfinished to the point when the mirror-down operation is finished (or tothe point when the secondary processing, such as the image processingoperation etc., is finished). Therefore, the predetermined length oftime needs only to elapse (the predetermined period is completed) beforethe completion of the mirror-down operation (or the point in time whenthe secondary processing is finished).

In the first embodiment, the predetermined length of time is set to 90ms, which is less than the length of time (approximately 120 ms) fromthe point when the mirror-down operation commences to the point when themirror-down operation is finished (see step S27 in FIG. 4). Further, theelapse of the predetermined length of time (the predetermined periodends) occurs before (or at the same time of) the completion of themirror-down operation (or the point when the secondary processing isfinished).

Next, the second embodiment is explained. In the first embodiment, themovable unit 30 a is moved to the first position P1, which is a positionof the movable unit 30 a immediately before the OFF state of the controldriving the anti-shake operation, after the anti-shake operation. In thesecond embodiment, the movable unit 30 a is moved to the second positionthat is calculated on the basis of the direction of the movement of themovable unit 30 a according to the force of gravity, after theanti-shake operation. The points that differ from the first embodimentare explained as follows.

When the release button 13 is partially depressed by the operator, thephotometric switch 12 a changes to the ON state so that the photometricoperation, the AF sensing operation, and the focusing operation areperformed.

When the release button 13 is fully depressed by the operator, therelease switch 13 a changes to the ON state so that the imagingoperation by the imaging unit 39 a (the imaging apparatus) is performed,and the image which is captured, is stored.

In the second embodiment, the anti-shake operation is performed onlywhen the release switch 13 a is set to the ON state during the time ofexposure. The movable unit 30 a is moved to the second position P2 overthe course of a second length of time after the exposure time for theimaging operation and a first period is finished.

The CPU 21 is a control apparatus that controls each part of thephotographing apparatus 1 regarding the imaging operation, and theanti-shake operation (i.e. the image stabilizing operation). Theanti-shake operation includes both the movement of the movable unit 30 aand position-detection efforts.

Further, the CPU 21 stores a value of the anti-shake parameter IS thatdetermines whether the photographing apparatus 1 is in the anti-shakemode or not, a value of a release state parameter RP, a value of amirror state parameter MP, a value of a mirror-down time parameter MRDN,a value of a first end position parameter RFSPx, a value of a second endposition parameter RFSPy, a value of a first present position parameterPPx, and a second present position parameter PPy.

The CPU 21 stops driving the movable unit 30 a for the anti-shakeoperation, after the exposure time of the imaging operation (set to theOFF state). When the movement of the movable unit 30 a for theanti-shake operation is stopped (set to the OFF state) and when anotherdriving operation of the movable unit 30 a is not performed, the movableunit 30 a drops to the end of the range of movement according to theforce of gravity (drop movement).

In the second embodiment, even after the movement of the movable unit 30a for the anti-shake operation has been set to the OFF state, the CPU 21does not immediately drive the movable unit 30 a. Instead, the CPU 21pauses for a first length of time (30 ms) before driving the movableunit 30 a over the course of (while taking the duration of) a secondlength of time (90 ms), based on a movement direction of the movableunit 30 a in a first period that has the first length of time.

Specifically, after the value of the mirror state parameter MP is set to1 and the first length of time has elapsed, the CPU 21 calculates asecond position P2 based on the movement direction of the movable unit30 a in the first period. The movement direction of the movable unit 30a is determined on the basis of a quantity of change between theposition of the movable unit 30 a before the first length of time begins(immediately after the value of the mirror state parameter MP is setto 1) and the position of the movable unit 30 a after the first lengthof time ends. Afterwards, the CPU 21 moves the movable unit 30 a to thesecond position P2 over the course of a second length of time (90 ms).

In the movement of the movable unit 30 a to the second position P2, themovable unit 30 a moves at a low speed immediately before finishing itsmovement (when the movable unit 30 a is approximately at the secondposition P2).

In other words, before finishing its movement, the movable unit 30 adecelerates (slows down) then stops upon completion of the movement.

Specifically, the CPU 21 does not control the movement of the movableunit 30 a in the first period, after the control for driving the movableunit 30 a during the anti-shake operation is set to the OFF state.

The CPU 21 resumes controlling the movement of the movable unit 30 aunder the condition where the relationship between the elapsed time andmovement distance of the movable unit 30 a is represented by a sinewaveform (see FIG. 11). Specifically, under the control of the CPU 21,the movable unit 30 a commences movement at the point in time signalingthe end of the first length of time and the beginning of the secondlength of time (MRDN=30, the elapsed time t=30), and finishes movementat the point in time signaling the end of the second length of time(MRDN=120, the elapsed time t=120)

In other words, the CPU 21 resumes controlling the movement of themovable unit 30 a under the condition where the relationship between theelapsed time and movement speed of the movable unit 30 a is representedby a cosine waveform (see FIG. 12). Specifically, under the control ofCPU 21, the movable unit 30 a commences movement at the point in timesignaling the end of the first length of time and the beginning of thesecond length of time (MRDN=30, the elapsed time t=30), and finishesmovement at the point in time signaling the end of the second length oftime (MRDN=120, the elapsed time t=120).

The first end position parameter RFSPx is set to the position of themovable unit 30 a (the second position P2) in the first direction x.

Similarly, the second end position parameter RFSPy is set to theposition of the movable unit 30 a (the second position P2) in the seconddirection y.

The second position P2 is the calculated position where the movable unit30 a should be moved after the second length of time has elapsed, basedon the movement direction of drop of the movable unit 30 a in the firstperiod according to force of gravity.

In the case where the magnitude of the movement of the movable unit 30 ain the first period according to the force of gravity is greater than orequal to the magnitude of a reference movement quantity ZA, the secondposition P2 is set to the end of the range of movement (see steps S87,S88, S90, S91, S94, S95, S97, and S98 in FIG. 13).

In the case where the magnitude of the movement of the movable unit 30 ain the first period according to the force of gravity is not greaterthan and equal to the magnitude of the reference movement quantity ZA,such as when the photographing apparatus 1 faces towards the up side ordown side etc., the second position P2 is set to same the position asthat occupied by the movable unit 30 a at the end of the first length oftime (see step S99 in FIG. 13).

The CPU 21 stores the value of a first movement quantity parameter XXand the value of a second movement quantity parameter YY.

The first movement quantity parameter XX is set equal to the differencebetween the value of the coordinate of position P_(n) after A/Dconversion in the first direction x: pdx_(n), and the value of the firstpresent position parameter PPx (see step S81 in FIG. 13).

Similarly, the second movement quantity parameter YY is set equal to thedifference between the value of the coordinate of position P_(n) afterA/D conversion in the second direction y: pdy_(n) and the value of thesecond present position parameter PPy.

The first present position parameter PPx is set equal to the positionoccupied by the movable unit 30 a in the first direction x at thecompletion of the anti-shake operation (see step S157 in FIG. 10).

Similarly, the second present position parameter PPy is set equal to theposition occupied by the movable unit 30 a in the second direction y atthe completion of the anti-shake operation.

The value of the reference movement quantity ZA, the value of the firsthorizontal end position X⁺LMT, the value of the second horizontal endposition X⁻LMT, the value of the first vertical end position Y⁺LMT, andthe value of the second vertical end position Y⁻LMT, which are used forcalculating the second position, are stored in the CPU 21 etc.

In the second embodiment, the position S_(n) where the imaging unit 39 a(the movable unit 30 a) should be moved during a second period that hasthe second length of time after the anti-shake operation is complete anda first period that has the first length of time has elapsed, is setwith respect to the movement of the movable unit 30 a to the secondposition P2 during the second period, and does not correspond to themagnitude of hand-shake (see step S163 in FIG. 10).

Next, the main operation of the photographing apparatus 1 in the secondembodiment is explained by using the flowchart in FIG. 9.

When the photographing apparatus 1 is set to the ON state, theelectrical power is supplied to the angular velocity detection unit 25so that the angular velocity detection unit 25 is set to the ON state instep S111.

In step S112, the interruption process of the timer at the predeterminedtime interval (1 ms) commences. In step S113, the value of the releasestate parameter RP is set to 0. The detail of the interruption processof the timer in the second embodiment is explained later by using theflowchart in FIG. 10.

In step S114, it is determined whether the photometric switch 12 a isset to the ON state. When it is determined that the photometric switch12 a is not set to the ON state, the operation returns to step S114 andthe process in step S114 is repeated. Otherwise, the operation continueson to step S115.

In step S115, it is determined whether the anti-shake switch 14 a is setto the ON state. When it is determined that the anti-shake switch 14 ais not set to the ON state, the value of the anti-shake parameter IS isset to 0 in step S116. Otherwise, the value of the anti-shake parameterIS is set to 1 in step S117.

In step S118, the AE sensor of the AE unit 23 is driven, the photometricoperation is performed, and the aperture value and exposure time arecalculated.

In step S119, the AF sensor and the lens control circuit of the AF unit24 are driven to perform the AF sensing and focus operations,respectively.

In step S120, it is determined whether the release switch 13 a is set tothe ON state. When the release switch 13 a is not set to the ON state,the operation returns to step S114 and the process insteps S114 to S119is repeated. Otherwise, the operation continues on to step S122, and therelease sequence operation commences.

In step S122, the value of the release state parameter RP is set to 1.

In step S123, the mirror-up operation and the aperture closing operationcorresponding to the aperture value that is either preset or calculated,are performed by the mirror-aperture-shutter unit 18.

After the mirror-up operation is finished, the opening operation of theshutter (the movement of the front curtain in the shutter) commences instep S124.

In step S125, the exposure operation, or in other words the electriccharge accumulation of the imaging device (CCD etc.), is performed.After the exposure time has elapsed, the value of the mirror stateparameter MP is set to 1 and the value of the mirror-down time parameterMRDN is set to 0 in step S126.

In step S127, the closing operation of the shutter (the movement of therear curtain in the shutter), the mirror-down operation, and the openingoperation of the aperture are performed by the mirror-aperture-shutterunit 18. In step S128, the value of the mirror state parameter MP is setto 0.

After the time of exposure, the anti-shake operation is complete, andthe movement of the movable unit 30 a for the anti-shake operation ispostponed until the release switch 13 a is once again set to the ONstate. In other words, the interruption process in FIG. 10 is performedwithout executing the actions of steps S165 to S167 from after theexposure time and until the next time the release switch 13 a is set tothe ON state.

The elapsed time from commencement to completion of the mirror-downoperation is approximately 120 ms. In the second embodiment, themovement of the movable unit 30 a to the second position P2 (RFSPx,RFSPy) is finished before (or at the same time of) the completion of themirror-down operation.

Further, when the completion of the movement of the movable unit 30 a tothe second position P2 is synchronized with the completion of themirror-down operation, the timing of the shock from the braking of themovement of the movable unit 30 a agrees with the timing of the shockbased on the completion of the mirror-down operation. Therefore,discomfort that the operator of the photographing apparatus 1 feels canbe restrained because the shock based on the breaking the movement ofthe movable unit 30 a is cancelled out.

In step S129, the electric charge which has accumulated in the imagingdevice during the exposure time is read. In step S130, the CPU 21communicates with the DSP 19 so that the image processing operation isperformed based on the electric charge read from the imaging device. Theimage, on which the image processing operation is performed, is storedto the memory in the photographing apparatus 1. In step S131, the imagethat is stored in the memory is displayed on the indicating unit 17. Instep S132, the value of the release state parameter RP is set to 0 sothat the release sequence operation is finished, and the operation thenreturns to step S14, in other words the photographing apparatus 1 is setto a state where the next imaging operation can be performed.

Next, the interruption process of the timer in the second embodiment,which commences in step S112 in FIG. 9 and is performed at everypredetermined time interval (1 ms) independent of the other operations,is explained by using the flowchart in FIG. 10.

When the interruption process of the timer commences, the first angularvelocity vx, which is output from the angular velocity detection unit25, is input to the A/D converter A/D 0 of the CPU 21 and converted tothe first digital angular velocity signal Vx_(n), in step S151. Thesecond angular velocity vy, which is also output from the angularvelocity detection unit 25, is input to the A/D converter A/D 1 of theCPU 21 and converted to the second digital angular velocity signalVy_(n) (the angular velocity detection operation).

The low frequencies of the first and second digital angular velocitysignals Vx_(n) and Vy_(n) are reduced in the digital high-pass filterprocessing operation (the first and second digital angular velocitiesVVx_(n) and VVy_(n)).

In step S152, it is determined whether the value of the release stateparameter RP is set to 1. When it is determined that the value of therelease state parameter RP is not set to 1, driving the movable unit 30a is set to OFF state, or the anti-shake unit 30 is set to a state wherethe driving control of the movable unit 30 a is not performed in stepS153. Otherwise, the operation proceeds directly to step S154.

In step S154, the hall element unit 44 a detects the position of themovable unit 30 a, and the first and second detected-position signals pxand py are calculated by the hall-element signal-processing unit 45. Thefirst detected-position signal px is then input to the A/D converter A/D2 of the CPU 21 and converted to a digital signal pdx_(n), whereas thesecond detected-position signal py is input to the A/D converter A/D 3of the CPU 21 and also converted to a digital signal pdy_(n), both ofwhich thus determine the present position P_(n) (pdx_(n), pdy_(n)) ofthe movable unit 30 a.

In step S155, it is determined whether the value of the mirror stateparameter MP is set to 1. When it is determined that the value of themirror state parameter MP is not set to 1, the operation proceedsdirectly to step S170. Otherwise, the operation continues to step S156.

In step S156, it is determined whether the value of the mirror-down timeparameter MRDN is set to 0.

When it is determined that the value of the mirror-down time parameterMRDN is set to 0, the value of the first present position parameter PPxis set to the value of the coordinate of the position P_(n) in the firstdirection x after A/D conversion, pdx_(n), and the value of the secondpresent position parameter PPy is set to the value of the coordinate ofthe position P_(n) in the second direction y after A/D conversion,pdy_(n) in step S157. Then the operation continues to step S158.Otherwise, the operation proceeds directly to step S158.

In step S158, it is determined whether the value of the mirror-down timeparameter MRDN is set to a value less than 30. When it is determinedthat the value of the mirror-down time parameter MRDN is set to a valueless than 30, the operation continues to step S159. Otherwise, theoperation proceeds directly to step S160.

In step S159, the value of the mirror-down time parameter MRDN isincreased by the value of 1. And then, the operation proceeds to stepS153.

In step S160, it is determined whether the value of the mirror-down timeparameter MRDN is set equal to 30.

When it is determined that the value of the mirror-down time parameterMRDN is set equal to 30 (i.e. the first length of time has elapsed), theoperation continues to step S161. Otherwise, the operation proceedsdirectly to step S162.

In step S161, the calculation of the second position (RFSPx, RFSPy), theposition where the movable unit 30 a is moved over the course of thesecond length of time, is carried out. The detail of the calculation instep S161 is explained later by using the flowchart in FIG. 13.

In step S162, it is determined whether the value of the mirror-down timeparameter MRDN is set to 120.

When it is determined that the value of the mirror-down time parameterMRDN is set to 120 (i.e. the first length of time has elapsed), theoperation proceeds to step S153. Otherwise, the operation continues tostep S163.

In step S163, the position S_(n) (Sx_(n), Sy_(n)) where the movable unit30 a (the imaging unit 39 a) should be moved, is calculated on the basisof the first and second present position parameters PPx and PPy, thefirst and second end position parameters RFSPx and RFSPy, and themirror-down time parameter MRDN (Sx_(n)=PPx+(RFSPx−PPx)×sin{(MRDN−30)×90 degrees÷90}, Sy_(n)=PPy+(RFSPy−PPy)×sin {(MRDN−30)×90degrees÷90}).

In step S164, the value of the mirror-down time parameter MRDN isincreased by the value of 1, then the operation proceeds directly tostep S168.

Because a large load is exerted upon the CPU 21 when it performs thetrigonometric function processing operation to calculate the value of“sin {(MRDN−30)×90 degrees÷90}”, it is desirable to store the values ofthe 91 different patterns of “sin {(MRDN−1)×90 degrees÷90}” from whenthe MRDN=30, to when MRDN=120 in order to increase the processing speed.

In step S170, it is determined whether the value of the mirror-down timeparameter MRDN is set to 120. When it is determined that the value ofthe mirror-down time parameter MRDN is set to 120, the operationproceeds to step S153. Otherwise, the operation proceeds to step S165.

In step S165, it is determined whether the value of the anti-shakeparameter IS is 0. When it is determined that the value of theanti-shake parameter IS is 0 (IS=0), in other words when thephotographing apparatus is not in anti-shake mode, the position S_(n)(Sx_(n), Sy_(n)) where the movable unit 30 a (the imaging unit 39 a)should be moved is set at the center of the range of movement of themovable unit 30 a, in step S166. When it is determined that the value ofthe anti-shake parameter IS is not 0 (IS=1), in other words when thephotographing apparatus is in anti-shake mode, the position S_(n)(Sx_(n), Sy_(n)) where the movable unit 30 a (the imaging unit 39 a)should be moved is calculated on the basis of the first and secondangular velocities vx and vy, in step S167.

In step S168, the first driving force Dx_(n) (the first PWM duty dx) andthe second driving force Dy_(n) (the second PWM duty dy) of the drivingforce D_(n), which moves the movable unit 30 a to the position S_(n),are calculated on the basis of the position S_(n) (Sx_(n), Sy_(n)) thatwas determined in step S163, step S166 or step S167, and the presentposition P_(n) (Pdx_(n), Pdy_(n)).

In step S169, the first driving coil unit 31 a is driven by applying thefirst PWM duty dx to the driver circuit 29, and the second driving coilunit 32 a is driven by applying the second PWM duty dy to the drivercircuit 29, so that the movable unit 30 a is moved to position S_(n)(Sx_(n), Sy_(n)).

The process of steps S168 and 5169 is an automatic control calculationthat is used with the PID automatic control for performing general(normal) proportional, integral, and differential calculations.

Next, the detail of the calculation for specifying the second positionP2 in step S161 in FIG. 10 is explained by using the flowchart in FIG.13.

In the flowchart of FIG. 13, the process for the calculation of thesecond position in the case where the range of movement of the movableunit 30 a forms the shape of a square is explained. It should be notedthat the range of movement of the movable unit 30 a may also form arectangular shape. In the case where the range of movement of themovable unit 30 a forms a rectangular shape, the values of theconditions in each step of FIG. 13 are changed corresponding to thelength to width ratio of the rectangular shape.

When the calculation of the second position P2 commences, the value ofthe first movement quantity parameter XX is calculated based on thecoordinate of position P_(n) after A/D conversion in the first directionx: pdx_(n), at the end of the first period (at the end of the firstlength of time following the anti-shake operation), and the firstpresent position parameter PPx (XX=pdx_(n)−PPx). Similarly, the value ofthe second movement quantity parameter YY is calculated based on thecoordinate of position P_(n) after A/D conversion in the seconddirection y: pdy_(n), at the end of the first period (at the end of thefirst length of time following the anti-shake operation), and the secondpresent position parameter PPy (YY=pdy_(n)−PPy), in step S81.

In step S82, it is determined whether the absolute value of the firstmovement quantity parameter XX is less than the reference movementquantity ZA.

When it is determined that the absolute value of the first movementquantity parameter XX is less than the reference movement quantity ZA,it is determined that the absolute value of the second movement quantityparameter YY is less than the reference movement quantity ZA in stepS83.

When it is determined that the absolute value of the first movementquantity parameter XX is not less than the reference movement quantityZA, the operation proceeds directly to step S84.

When it is determined that the absolute value of the second movementquantity parameter YY is less than the reference movement quantity ZA,the operation proceeds directly to step S99.

When it is determined that the absolute value of the second movementquantity parameter YY is not less than the reference movement quantityZA, the operation continues to step S84.

In step S84, it is determined whether the absolute value of the firstmovement quantity parameter XX is equal to the absolute value of thesecond movement quantity parameter YY.

When it is determined that the absolute value of the first movementquantity parameter XX is equal to the absolute value of the secondmovement quantity parameter YY, the operation proceeds directly to stepS92.

When it is determined that the absolute value of the first movementquantity parameter XX is not equal to the absolute value of the secondmovement quantity parameter YY, the operation continues to step S85.

In step S85, it is determined whether the absolute value of the firstmovement quantity parameter XX is greater than the absolute value of thesecond movement quantity parameter YY.

When it is determined that the absolute value of the first movementquantity parameter XX is greater than the absolute value of the secondmovement quantity parameter YY, the operation proceeds directly to stepS89.

When it is determined that the absolute value of the first movementquantity parameter XX is not greater than the absolute value of thesecond movement quantity parameter YY, the operation continues to stepS86.

In step S86, it is determined whether the value of the second movementquantity parameter YY is less than 0. When it is determined that thevalue of the second movement quantity parameter YY is less than 0, theoperation proceeds directly to step S88. When it is determined that thevalue of the second movement quantity parameter YY is not less than 0,the operation continues to step S87.

In step S87, the value of the first end position parameter RFSPx is setequal to the value of the coordinate of position P_(n) after A/Dconversion in the first direction x: pdx_(n) at the end of the firstperiod (at the end of the first length of time following the completionof the anti-shake operation), and the value of the second end positionparameter RFSPy is set equal to the value of the first vertical endposition Y⁺LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the point in time when the first period iscomplete (after the first length of time has elapsed followingcompletion of the anti-shake operation), and the coordinate of thesecond position P2 in the second direction y is set equal to the valueof the coordinate of the position in the second direction y at the endof the range of movement on the side where the movable unit 30 a ismoved in the first period.

In step S88, the value of the first end position parameter RFSPx is setequal to the value of the coordinate of position P_(n), after A/Dconversion in the first direction x: pdx_(n) at the end of the firstperiod (at the end of the first length of time following the completionof the anti-shake operation), and the value of the second end positionparameter RFSPy is set equal to the value of the second vertical endposition Y⁻LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the point in time when the first period iscomplete (after the first length of time has elapsed following thecompletion of the anti-shake operation), and the coordinate of thesecond position P2 in the second direction y is set equal to the valueof the coordinate of the position in the second direction y at the endof the range of movement on the side where the movable unit 30 a ismoved in the first period.

In step S89, it is determined whether the value of the first movementquantity parameter XX is less than 0. When it is determined that thevalue of the first movement quantity parameter XX is less than 0, theoperation proceeds directly to step S91. When it is determined that thevalue of the first movement quantity parameter XX is not less than 0,the operation continues to step S90.

In step S90, the value of the first end position parameter RFSPx is setto the value of the first horizontal end position X⁺LMT, and the valueof the second end position parameter RFSPy is set to the value of thecoordinate of position P_(n) after A/D conversion in the seconddirection y: pdy_(n) at the end of the first period (at the end of thefirst length of time following the completion of the anti-shakeoperation).

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the point in time when the first period is complete(after the first length of time has elapsed following the completion ofthe anti-shake operation).

In step S91, the value of the first end position parameter RFSPx is setequal to the value of the second horizontal end position X⁻LMT, and thevalue of the second end position parameter RFSPy is set equal to thevalue of the coordinate of position P_(n) after A/D conversion in thesecond direction y: pdy_(n) at the end of the first period (at the endof the first length of time following the completion of the anti-shakeoperation).

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the point in time when the first period is complete(after the first length of time has elapsed following the completion ofthe anti-shake operation).

In step S92, it is determined whether the value of the second movementquantity parameter YY is less than 0. When it is determined that thevalue of the second movement quantity parameter YY is less than 0, theoperation proceeds directly to step S96. When it is determined that thevalue of the second movement quantity parameter YY is not less than 0,the operation continues to step S93.

In step S93, it is determined whether the value of the first movementquantity parameter XX is less than 0. When it is determined that thevalue of the first movement quantity parameter XX is less than 0, theoperation proceeds directly to step S95. When it is determined that thevalue of the first movement quantity parameter XX is not less than 0,the operation continues to step S94.

In step S94, the value of the first end position parameter RFSPx is setequal to the value of the first horizontal end position X⁺LMT, and thevalue of the second end position parameter RFSPy is set equal to thevalue of the first vertical end position Y⁺LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the end of the range of movement on the side where themovable unit 30 a is moved in the first period.

In step S95, the value of the first end position parameter RFSPx is setequal to the value of the second horizontal end position X⁻LMT, and thevalue of the second end position parameter RFSPy is set equal to thevalue of the first vertical end position Y⁺LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the end of the range of movement on the side where themovable unit 30 a is moved in the first period.

In step S96, it is determined whether the value of the first movementquantity parameter XX is less than 0. When it is determined that thevalue of the first movement quantity parameter XX is less than 0, theoperation proceeds directly to step S98. When it is determined that thevalue of the first movement quantity parameter XX is not less than 0,the operation continues to step S97.

In step S97, the value of the first end position parameter RFSPx is setequal to the value of the first horizontal end position X⁺LMT, and thevalue of the second end position parameter RFSPy is set equal to thevalue of the second vertical end position Y⁻LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the end of the range of movement on the side where themovable unit 30 a is moved in the first period.

In step S98, the value of the first end position parameter RFSPx is setequal to the value of the second horizontal end position X⁻LMT, and thevalue of the second end position parameter RFSPy is set equal to thevalue of the second vertical end position Y⁻LMT.

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the end of the range of movement on the sidewhere the movable unit 30 a is moved in the first period, and thecoordinate of the second position P2 in the second direction y is setequal to the value of the coordinate of the position in the seconddirection y at the end of the range of movement on the side where themovable unit 30 a is moved in the first period.

In step S99, the value of the first end position parameter RFSPx is setequal to the value of the coordinate of position P_(n) after A/Dconversion in the first direction x: pdx_(n) at the end of the firstperiod (at the end of the first length of time following the completionof the anti-shake operation), and the value of the second end positionparameter RFSPy is set equal to the value of the coordinate of positionP_(n) after A/D conversion in the second direction y: pdy_(n) at the endof the first period (at the end of the first length of time followingthe completion of the anti-shake operation).

In other words, the coordinate of the second position P2 in the firstdirection x is set equal to the value of the coordinate of the positionin the first direction x at the point in time when the first period iscomplete (after the first length of time has elapsed following thecompletion of the anti-shake operation), and the coordinate of thesecond position P2 in the second direction y is set equal to the valueof the coordinate of the position in the second direction y at the pointin time when the first period is complete (after the first length oftime has elapsed following the completion of the anti-shake operation).

In an anti-shake apparatus that does not have a fixed-positioningmechanism so that the movable unit 30 a remains stationary when themovable unit 30 a is not being driven, such as the second embodiment,when the movement of the movable unit 30 a is set to the OFF state afterthe anti-shake operation, the movable unit 30 a is allowed to movefreely according to the force of gravity until it is stopped upon makingcontact with the end of its range of movement. In the case where theimpact between the movable unit 30 a and the contacting part is large,the contacting part may be broken and the operator of the photographingapparatus 1 may experience discomfort due to the shock of the movableunit 30 a.

In the second embodiment, when the anti-shake operation is complete, thecontrol driving the movable unit 30 a is set to the OFF state and thefirst length of time has elapsed (the first period is finished), themovable unit 30 a is moved to the second position P2 over the course ofthe second length of time (90 ms). The second position P2 is determinedon the basis of the movement direction of the movable unit 30 a in thefirst period. The movement direction of the movable unit 30 a isdetermined on the basis of a quantity of change between the position ofthe movable unit 30 a at the point in time signaling the end of theanti-shake operation and the beginning of the first time period and theposition of the movable unit 30 a at the end of the first period.

Therefore, the position where the movable unit is moved according to theforce of gravity when the anti-shake operation is finished and thecontrol driving the movable unit 30 a is set to the OFF state, issomewhere at the end of the range of movement and almost the same as thesecond position P2.

Further, the movement of the movable unit 30 a to the second position P2is performed over the course of the second length of time (90 ms), at acomparatively low speed (see FIG. 12). Particularly towards the end ofthe movement (when the movable unit 30 a is near the second positionP2), the movement of the movable unit 30 a is performed at the low speedso that the shock based on the movement can be restrained.

Further, in the second embodiment, because the movement direction of themovable unit 30 a immediately after the anti-shake operation isspecified, even if the position of the photographing apparatus 1 held bythe operator after the exposure time changes from the position of thephotographing apparatus 1 held by the operator before the exposure time,the second position P2 can be (calculated) based on the direction ofgravity.

Further, it is not necessary to add a separate detection apparatus fordetecting the direction of gravity, such as a gravity detection sensoretc.

In the second embodiment, the CPU 21 controls the movement of themovable unit 30 a under the condition where the relationship between theelapsed time and movement distance of the movable unit 30 a isrepresented by a sine waveform (see FIG. 11). Specifically, under thecontrol of the CPU 21, the movable unit 30 a commences movement at thepoint in time signaling the end of the first length of time and thebeginning of the second length of time (MRDN=30, the elapsed time t=30),and finishes movement at the point in time signaling the end of thesecond length of time (MRDN=120, the elapsed time t=120), after thecompletion of the anti-shake operation and the end of the first lengthof time.

In other words, the CPU 21 controls the movement of the movable unit 30a under the condition where the relationship between the elapsed timeand movement speed of the movable unit 30 a is represented by a cosinewaveform (see FIG. 12). Specifically, under the control of the CPU 21,the movable unit 30 a commences movement at the point in time signalingthe end of the first length of time and the beginning of the secondlength of time (MRDN=30, the elapsed time t=30), and finishes movementat the point in time signaling the end of the second length of time(MRDN=120, the elapsed time t=120), after the completion of theanti-shake operation and the end of the first length of time.

However, the waveform representing the relationship between the elapsedtime and the movement distance of the movable unit 30 a from the pointwhen the movement of the movable unit 30 a commences, is not limited tothe sine waveform.

For example, the waveform that represents the relationship between themovement distance of the movable unit 30 a and the corresponding elapsedtime from the point when the movement of the movable unit 30 acommences, may be a saturation curve that the movement of the movableunit 30 a follows at the low speed immediately before the completion ofthe movement of the movable unit 30 a (MRDN=120).

Further, in the second embodiment, the photographing apparatus 1 is asingle lens reflex camera that performs the mirror-up operation;however, the photographing apparatus 1 may not perform the mirror-upoperation.

In the case where the photographing apparatus 1 that does not performthe mirror-up operation is used for the second embodiment, the movementof the movable unit 30 a to the second position P2 commences after theanti-shake operation is finished and the first length of time haselapsed, and the movement of the movable unit 30 a to the secondposition P2 is complete before the secondary processing, such as theimage processing operation etc. is complete.

Further, the length of the first period is not limited to 30 ms, and thelength of the second period is not limited 90 ms. The sum of the firstand second length of times is set to a length of time that is less thanor equal to the length of time from the point when the anti-shakeoperation is finished to the point when the mirror-down operation isfinished (or to the point when the secondary processing, such as theimage processing operation etc. is finished). Therefore, the sum of thefirst and second length of times needs only to elapse (the second periodis completed) before the completion of the mirror-down operation (or thepoint in time when the secondary processing is finished).

In the second embodiment, the sum of the first and second length oftimes is set to 120 ms (30 ms+90 ms), which is equal to the time length(approximately 120 ms) from the point when the mirror-down operationcommences to the point when the mirror-down operation is complete.Further, the elapse of the second length of time (the second periodends) occurs before (or at the same time of) the completion of themirror-down operation (or the time point when the secondary processingis finished).

Further, it is explained that the movable unit 30 a has the imagingdevice; however, the movable unit 30 a may have a hand-shake correctinglens instead of the imaging device.

Further, it is explained that the hall element is used for positiondetection as the magnetic-field change-detecting element. However,another detection element, an MI (Magnetic Impedance) sensor such ashigh-frequency carrier-type magnetic-field sensor, a magneticresonance-type magnetic-field detecting element, or an MR(Magneto-Resistance effect) element may be used for position detectionpurposes. When one of either the MI sensor, the magnetic resonance-typemagnetic-field detecting element, or the MR element is used, theinformation regarding the position of the movable unit can be obtainedby detecting the magnetic-field change, similar to using the hallelement.

Although the embodiments of the present invention have been describedherein with reference to the accompanying drawings, obviously manymodifications and changes may be made by those skilled in this artwithout departing from the scope of the invention.

The present disclosure relates to subject matter contained in JapanesePatent Application Nos. 2006-192863 (filed on Jul. 13, 2006) and2006-192712 (filed on Jul. 13, 2006), which are expressly incorporatedherein by reference, in their entirety.

1. An anti-shake apparatus for image stabilizing, comprising: a movableunit that is movable; and a controller that controls said movable unitfor an anti-shake operation; when a first period having a first lengthof time after a movement of said movable unit for said anti-shakeoperation is finished, said controller moving said movable unit to asecond position over the course of a second length of time; said secondposition being determined based on a quantity of change between aposition of said movable unit before said first period commencesimmediately after said anti-shake operation is finished, and a positionof said movable unit after said first period is finished; and saidcontroller moving said movable unit at a decelerated, low rate of speedbefore finishing its movement to said second position.
 2. The anti-shakeapparatus according to claim 1, further comprising a mirror thatperforms a mirror-up operation and a mirror-down operation; a sum ofsaid first length of time and said second length of time being shorterthan or equal to a length of time from a point when said anti-shakeoperation is finished and a control driving said movable unit for saidanti-shake operation is set to an OFF state to a point when saidmirror-down operation is finished.
 3. The anti-shake apparatus accordingto claim 2, wherein a second period having said second length of time isfinished when said mirror-down operation is finished.
 4. The anti-shakeapparatus according to claim 1, wherein a sum of said first length oftime and said second length of time is shorter than a length of timefrom a point when said anti-shake operation is finished and the controldriving said movable unit for said anti-shake operation is set to an OFFstate to a point when the image processing operation is finished.
 5. Theanti-shake apparatus according to claim 1, wherein said controllercontrols a movement of said movable unit, under the condition where arelationship between an elapsed time and a movement distance of saidmovable unit from when the movement of said movable unit for said secondposition commences shows a sine waveform in a second period having saidsecond length of time from when the movement of said movable unit forsaid second position commences, to when the movement of said movableunit for said second position is finished.
 6. The anti-shake apparatusaccording to claim 5, wherein a movement control of said movable unitfor said anti-shake operation and the movement to said second positionis performed at a predetermined time interval; said first length of timeis longer than said predetermined time interval; and said second lengthof time is longer than said predetermined time interval.
 7. Theanti-shake apparatus according to claim 1 wherein said second positionis set to the same position as that of said movable unit at an end ofsaid first period, when said quantity of change is small; and when saidquantity of change is not small, said second position is set to an endof the range of movement of said movable unit on a side where saidmovable unit is moved in said first length of time.
 8. An anti-shakeapparatus for image stabilizing, comprising: a movable unit that ismovable for an anti-shake operation; and a controller that stops saidanti-shake operation after an exposure time and moves said movable unitto a first position after said anti-shake operation; said controllercontrolling a movement of said movable unit, under the condition where arelationship between the distance of said movement and the elapse oftime corresponding to said movement to said first position isrepresented by a sine waveform during a predetermined period beginningwith a commencement of movement of said movable unit to said firstposition and ending with a completion of movement of said movable unitto said first position; and said movement of said movable unit to saidfirst position being performed based on a position detection operationof said movable unit and a positioning operation in which a position towhere said movable unit should be moved is determined, at apredetermined time interval that is shorter than said predeterminedperiod.